We argue for the adoption of a predictive approach to model specification. Specifically, we derive the difference between means and the ratio of determinants of covariance matrices when a subset of explanatory variables is included or excluded from a regression. Results for an economic...

The generalized method of moments (GMM) estimation technique is discussed for count data models with endogenous regressors. Count data models can be specified with additive or multiplicative errors. It is shown that, in general, a set of instruments is not orthogonal to both error types....

This study examines the relationship between specifications for long-run output patterns and specifications for business cycle dynamics. In an application to US GDP, it is found that inferences about the nature of the trend in output are not robust to changes in the specification for short-run...

The paper analyses the relationship between the main determinants of technological activity and patent applications. To this end, an original panel of 181 international manufacturing firms investigating substantial amounts in R&D during the late 1980s has been constructed. The number of patent...

In this paper the business cycle properties of UK data are investigated using a VAR technique. A Real Business Cycle (RBC) model is formulated. The model includes both permanent and transitory shocks to technology. The business cycle properties of the data and the model are investigated by...